1. Field of the Invention
The present invention relates generally to magnetic heads that are utilized with thin film hard disk data storage devices, and more particularly to the design and fabrication of write head elements that are utilized in such magnetic heads.
2. Description of the Prior Art
It is a goal of the hard disk drive industry to develop magnetic heads that provide ever faster data writing speeds, such that increased quantities of data can be written onto the hard disk in shorter periods of time. Typical magnetic heads include two magnetic pole pieces having a narrow writing gap formed between the tips of the two pole pieces. Magnetic flux is caused to flow across the gap which causes changes in a thin film magnetic layer formed on a hard disk that is located proximate the gap. An induction coil is formed between the magnetic pole pieces to create a magnetic field between the pole pieces, and changes in the electric current that flows through the induction coil create changes in the magnetic flux that flows through the two pole pieces, whereby the magnetic flux that flows across the write gap is created. One of the parameters that controls the rate at which data can be written is the rate with which magnetic flux changes can be made by the write head. This flux change rate is in part controlled by the magnetic flux rise time of the write head, and the physical geometry of the write head is one of the significant parameters that determines the magnetic flux rise time. Generally, a second magnetic pulse cannot successfully be initiated until the first magnetic pulse had reached a value near its peak, and the magnetic flux rise time is the time necessary for a magnetic pulse to reach this value. Therefore, if the magnetic flux rise time can be shortened, the data writing rate of a magnetic head can be increased.
Prior art magnetic heads have been fabricated with induction coils having multiple layers and torroidal coil turn designs, amongst others, in an effort to alter the physical geometry of the write head components such that the magnetic flux rise time is shortened. However, these prior art approaches generally cannot produce very fine pitch coils and short yoke lengths. The present invention utilizes a different fabrication method to achieve physical geometries for write head pole components that shorten the magnetic flux rise time of the write head element of a magnetic head, such that the data writing rate of the magnetic head is increased.
A hard disk drive of the present invention includes a magnetic head having a high aspect ratio induction coil. The magnetic head includes a first pole tip piece that is formed upon a first magnetic pole and a second pole tip piece that is part of the second magnetic pole, where the write gap is formed between the first pole tip piece and the second pole tip piece. The use of the two pole tip pieces increases the spacing between the first magnetic pole layer and the second magnetic pole layer such that an induction coil having high aspect ratio coil turns can be formed within the insulation layers. A reactive ion etch (RIE) process is used to form the coil trenches within which the high aspect ratio coil turns are created. An RIE etch stop layer is formed upon the first magnetic pole layer to prevent the RIE etch process from creating coil turn trenches that make contact with the first magnetic pole layer. Where high aspect ratio coil pattern is formed, a finer pitch coil is fabricated, such that the yoke length of the magnetic head is reduced and the flux rise time of the magnetic head is decreased, whereby the magnetic head has an increased data writing rate.
It is an advantage of the magnetic head of the present invention that it is fabricated with high aspect ratio induction coil turns between the magnetic poles of the write head element.
It is another advantage of the magnetic head of the present invention that the yoke length of the second magnetic pole of the write head element is reduced.
It is a further advantage of the magnetic head of the present invention that the magnetic flux rise time of the write head element is shortened.
It is yet another advantage of the magnetic head of the present invention that an increase in the data writing rate is achieved.